# Maintainer: Natanael Copa <ncopa@alpinelinux.org>

pkgname=linux-rpi
pkgver=6.6.9
case $pkgver in
*.*.*)	_kernver=${pkgver%.*};;
*.*)	_kernver=$pkgver;;
esac
pkgrel=0
pkgdesc="Linux kernel with Raspberry Pi patches"
url=https://github.com/raspberrypi/linux
depends="initramfs-generator linux-firmware-brcm"
_depends_dev="perl gmp-dev elfutils-dev bash mpc1-dev mpfr-dev"
makedepends="$_depends_dev gcc>=13.1.1_git20230603 sed installkernel bc linux-headers linux-firmware
	bison flex openssl-dev>3 findutils xz
"
options="!strip !check"
_rpi_repo="https://github.com/raspberrypi/linux.git"
_linux_repo="https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
source="https://cdn.kernel.org/pub/linux/kernel/v${pkgver%%.*}.x/linux-$_kernver.tar.xz
	https://cdn.kernel.org/pub/linux/kernel/v${pkgver%%.*}.x/patch-$pkgver.xz
	https://dev.alpinelinux.org/archive/rpi-patches/rpi-$pkgver-alpine.patch

	common-changes.config
	"
arch="armhf armv7 aarch64"
license="GPL-2.0-only"
_flavors="rpi"

for _f in $_flavors; do
	if [ "linux-$_f" != "$pkgname" ]; then
		subpackages="$subpackages linux-$_f::$CBUILD_ARCH"
	fi
	subpackages="$subpackages linux-$_f-dev:_dev:$CBUILD_ARCH"
done

case "$CARCH" in
	aarch64) _carch="arm64" ;;
	arm*) _carch="arm" ;;
esac

prepare() {
	local _patch_failed=
	cd "$srcdir"/linux-$_kernver
	if [ "${pkgver%.0}" = "$pkgver" ]; then
		msg "Applying patch-$pkgver.xz"
		unxz -c < "$srcdir"/patch-$pkgver.xz | patch -p1 -N
	fi

	# first apply patches in specified order
	for i in $source; do
		case $i in
		*.patch)
			msg "Applying $i..."
			if ! patch -s -p1 -N -i "$srcdir"/${i##*/}; then
				echo $i >>failed
				_patch_failed=1
			fi
			;;
		esac
	done

	if ! [ -z "$_patch_failed" ]; then
		error "The following patches failed:"
		cat failed
		return 1
	fi

	# remove localversion from patch if any
	rm -f localversion*

	local flavor=
	for flavor in $_flavors; do
		local _builddir="$srcdir"/build-$flavor.$CARCH
		mkdir -p "$_builddir"
		echo "-$pkgrel-$flavor" > "$_builddir"/localversion-alpine
		_genconfig $flavor
		make -C "$srcdir"/linux-$_kernver \
			O="$_builddir" \
			ARCH="$_carch" \
			olddefconfig
		_verifyconfig $flavor
	done
}

# generate config from defconfig and apply local changes.
# common-changes.config holds a list of = delimited
# config command and values used by kernel scripts/config script.
_genconfig() {
	local flavor=$1 defconfig=
	local builddir="$srcdir"/build-$flavor.$CARCH
	local defconfig=
	case "$CARCH" in
		armhf) defconfig=bcmrpi_defconfig;;
		armv7) defconfig=bcm2709_defconfig;;
		aarch64) defconfig=bcm2711_defconfig;;
		*) die "Unknown CARCH: $CARCH" ;;
	esac

	cp "$srcdir"/linux-$_kernver/arch/$_carch/configs/$defconfig \
		"$builddir"/.config

	while read line; do
		# skip comments
		case "$line" in
			"#"*) continue;;
		esac
		local option=${line%%=*} str=
		local cmd=$(echo $line | cut -d= -f2)
		case "$cmd" in
			y) cmd="enable";;
			n) cmd="disable";;
			m) cmd="module";;
			'"'*) cmd="set-str"; str="${line#*=}";;
			[0-9]*) cmd="set-val"; str="${line#*=}";;
			*) die "Command $cmd not accepted" ;;
		esac
		msg "[$flavor] $cmd: $option $str"
		"$srcdir"/linux-$_kernver/scripts/config \
			--file "$builddir"/.config \
			--$cmd "$option" "${str//\"/}"
	done < "$srcdir"/common-changes.config
}

# verify if options are set to correct value
_verifyconfig() {
	local flavor=$1
	local builddir="$srcdir"/build-$flavor.$CARCH
	while read line; do
		[ ${line:0:1} = "#" ] && continue
		local option=${line%%=*} str= invert=
		local cmd=$(echo $line | cut -d= -f2)
		case "$cmd" in
			enable) str="$option=y" ;;
			disable) str="$option"; invert="-v" ;;
			module) str="$option=m" ;;
			set-val) str="$option=${line##*=}" ;;
			set-str) str=${line##*=}
				str="$option=\"${str//\"/}\"" ;;
		esac
		grep -q $invert "^$str" "$builddir"/.config || \
			die "Config: $option not properly set!"
	done < "$srcdir"/common-changes.config
}

build() {
	unset LDFLAGS
	# for some reason these sometimes leak into the kernel build,
	# -Werror=format-security breaks some stuff
	unset CFLAGS CPPFLAGS CXXFLAGS
	for i in $_flavors; do
		cd "$srcdir"/build-$i.$CARCH
		local _kver=$(make kernelversion)
		if [ "$_kver" != "$pkgver" ]; then
			error "Version in Makefile ($_kver) does not correspond with pkgver ($pkgver)"
			return 1
		fi
		make ARCH="$_carch" CC="${CC:-gcc}" \
			KBUILD_BUILD_VERSION="$((pkgrel + 1 ))-Alpine"
	done
}

_package() {
	local _buildflavor="$1" _outdir="$2"
	local _builddir="$srcdir"/build-$_buildflavor.$CARCH

	cd "$_builddir"
	local _abi_release="$(make -s kernelrelease)"
	mkdir -p "$_outdir"/boot "$_outdir"/lib/modules

	local _install
	case "$CARCH" in
	arm*)
		_install="zinstall dtbs_install"
		;;
	aarch64)
		_install="install dtbs_install"
		;;
	*)
		_install=install
		;;
	esac

	# modules_install seems to regenerate a defect Modules.symvers. Work
	# around it by backing it up and restore it after modules_install
	cp Module.symvers Module.symvers.backup

	local INSTALL_DTBS_PATH="$_outdir"/boot
	make modules_install $_install \
		ARCH="$_carch" \
		INSTALL_MOD_PATH="$_outdir" \
		INSTALL_PATH="$_outdir"/boot \
		INSTALL_DTBS_PATH="$INSTALL_DTBS_PATH"
	cp Module.symvers.backup Module.symvers

	rm -f "$_outdir"/lib/modules/$_abi_release/build \
		"$_outdir"/lib/modules/$_abi_release/source
	rm -rf "$_outdir"/lib/firmware

	install -D -m644 include/config/kernel.release \
		"$_outdir"/usr/share/kernel/$_buildflavor/kernel.release

	# allow the initramfs generators to know the package name the kernel came from
	echo "${subpkgname:-$pkgname}" > "$_outdir"/lib/modules/$_abi_release/pkgname

	if [ "$CARCH" = "aarch64" ]; then
		mv -f "$INSTALL_DTBS_PATH"/broadcom/*.dtb \
			"$INSTALL_DTBS_PATH"
		rmdir "$INSTALL_DTBS_PATH"/broadcom
	fi
}

# main flavor installs in $pkgdir
package() {
	case "$CARCH" in
	armv7)
		provides="linux-rpi2=$pkgver-r$pkgrel"  # for backward compatibility
		replaces="linux-rpi2"  # for backward compatibility
	;;
	aarch64)
		provides="linux-rpi4=$pkgver-r$pkgrel"  # for backward compatibility
		replaces="linux-rpi4"  # for backward compatibility
	;;
	esac
	_package rpi "$pkgdir"
}


_dev() {
	local _flavor=$(echo $subpkgname | sed -E 's/(^linux-|-dev$)//g')
	local _builddir="$srcdir"/build-$_flavor.$CARCH

	cd "$_builddir"
	local _abi_release="$(make -s kernelrelease)"
	# copy the only the parts that we really need for build 3rd party
	# kernel modules and install those as /usr/src/linux-headers,
	# simlar to what ubuntu does
	#
	# this way you dont need to install the 300-400 kernel sources to
	# build a tiny kernel module
	#
	pkgdesc="Headers and script for third party modules for $_flavor kernel"
	depends="$_depends_dev"

	# handle backward compatibility with legacy flavors
	case "$_flavor" in
		rpi)
			case "$CARCH" in
				armv7)
					provides="linux-rpi2-dev=$pkgver-r$pkgrel"
					replaces="linux-rpi2-dev"
				;;
				aarch64)
					provides="linux-rpi4-dev=$pkgver-r$pkgrel"
					replaces="linux-rpi4-dev"
				;;
			esac
			;;
		*) die "Unknown flavor: $flavor" ;;
	esac

	local dir="$subpkgdir"/usr/src/linux-headers-$_abi_release

	# first we import config, run prepare to set up for building
	# external modules, and create the scripts
	mkdir -p "$dir"
	cp "$_builddir"/.config "$dir"/.config
	echo "-$pkgrel-$_flavor" > "$dir"/localversion-alpine

	make -j1 -C "$srcdir"/linux-$_kernver ARCH="$_carch" O="$dir" \
		syncconfig prepare modules_prepare scripts

	# remove the stuff that points to real sources. we want 3rd party
	# modules to believe this is the soruces
	rm "$dir"/Makefile "$dir"/source

	# copy the needed stuff from real sources
	#
	# this is taken from ubuntu kernel build script
	# http://kernel.ubuntu.com/git/ubuntu/ubuntu-zesty.git/tree/debian/rules.d/3-binary-indep.mk
	cd "$srcdir"/linux-$_kernver
	find .  -path './include/*' -prune \
		-o -path './scripts/*' -prune -o -type f \
		\( -name 'Makefile*' -o -name 'Kconfig*' -o -name 'Kbuild*' -o \
		   -name '*.sh' -o -name '*.pl' -o -name '*.lds' \) \
		-print | cpio -pdm "$dir"

	cp -a scripts include "$dir"
	find $(find arch -name include -type d -print) -type f \
		| cpio -pdm "$dir"

	install -Dm644 "$_builddir"/Module.symvers \
		"$dir"/Module.symvers

	mkdir -p "$subpkgdir"/lib/modules/$_abi_release
	ln -sf /usr/src/linux-headers-$_abi_release \
		"$subpkgdir"/lib/modules/$_abi_release/build
}

sha512sums="
458b2c34d46206f9b4ccbac54cc57aeca1eaecaf831bc441e59701bac6eadffc17f6ce24af6eadd0454964e843186539ac0d63295ad2cc32d112b60360c39a35  linux-6.6.tar.xz
adf3505296a700b6e01a72f3888e803eb2b1affcb8b4a086e2b116c2ed314494a447516e8ef15029ab3643da2b6c7c8585ea16c32bd32d07efffa4e9531a13a3  patch-6.6.9.xz
10b063ba499a5a58cf0103b340944a913568bbd042b606a05ffbb58cd6d54d971a5918f7e393727153174a1f689e39523dcdca3b908101cf017514aa4d60bca7  rpi-6.6.9-alpine.patch
f014a9b3574df17a3f6e0d8a2c48aef4239f33a062d64704fd56ecd596d090bb0413c8cb2abd6ec3ceeee09fa66243b6a3f7b405657edbd9c7a6407d6ec79fef  common-changes.config
"
